Barbs attached to stents help secure placement of a stent graft in a treated vasculature. Proper stent attachment and placement of the barb ensures that the stent graft will stay in place for the lifespan of the stent graft. Some stent designs limit the barb attachment location and method of attachment due to the material used in the barb and stent and due to the material used to attach the two. Other factors may also limit the barb attachment location, including strut crossover during crimping or potential stent fatigue failure due to weld location near a region on the wire stent of high stress or strain.
Some methods of attaching barbs to wire stents include silver soldering the barb to the wire stent, laser cutting the barb directly into a cannula-cut stent design, and laser welding a barb to the strut of the wire stent. Each of these methods may present particular limitations to barb placement and barb fatigue life depending on the stent design. In particular, welding or soldering a barb to a stent wire not only introduces an additional step in the manufacturing of a prosthesis such as a stent graft, but also introduces stress risers at locations where the welding heat is applied. The industry would benefit from expanded capabilities in barb attachment methods.
What is needed is a simplified barbed anchor that can be easy to manufacture, readily and securely attachable to a prosthesis, preferably by interference fit, and produce predictable results with respect to fatigue life and ability to anchor the prosthesis at the site of deployment.